Diffusion Properties And Iron Deposition Of The Putamen And Globus Pallidus In Healthy Adults

Objective: To evaluate the diffusion properties and iron deposition in theputamen and globus pallidus, and to further investigate their correlations usingdiffusion tensor imaging (DTI) and susceptibility weighted imaging (SWI). Byexploring the normal aging of the putamen and globus pallidus, to lay thefoundation for the further study of lentiform nucleus related diseases.Methods: Brain conventional MRI, DTI and SWI were employed in atotal of124right-handed healthy volunteers (61male and63female, agerange20~79years, average age48.7±17.4). By drawing the regions of interest,Fractional anisotropy (FA), mean diffusivity (MD), λ1, λ2, λ3in the putamenand globus pallidus and Phase value in the frontal white matter, caput nucleuscaudate, putamen, globus pallidus, thalamus, red nucleus, substantia nigrawere measured. The SPSS13.0statistics software was used for the statisticalinference. Correlation analysis of Phase value and postmortem brain ironconcentration was used to test the reliability of Phase value in quantifyingbrain iron deposition. The t test was used to compare each statistical index inthe putamen and globus pallidus, in right and left, in male and female. TheANOVA was used to compare each index among different age groups. Thecorrelations between FA, MD, λ1, λ2, λ3, Phase value and age were estimated.Finally, Pearson correlation analysis was used to study the correlationsbetween FA, MD, λ1, λ2, λ3and Phase value.Results:1Phase value was significantly negative correlated with postmortem brainiron concentration in healthy adults above30years old (r=-0.837, P=0.019).2FA, MD, λ1, λ2, λ3, Phase value were significantly different from putamenand globus pallidus (P＜0.05). FA in the putamen (0.1042±0.0183) was lowerthan that of in the globus pallidus (0.1867±0.0320), MD in the putamen (7.96±0.39) was lower than that of in the globus pallidus (8.54±0.66), λ1inthe putamen (8.80±0.55) was lower than that of in the globus pallidus(10.10±0.75), λ2in the putamen (7.97±0.49) was lower than that of in theglobus pallidus (8.51±0.69), λ3in the putamen (7.17±0.45) was higher thanthat of in the globus pallidus (6.98±0.67), Phase value in the putamen (-0.1264±0.0552) was higher than that of in the globus pallidus (-0.1644±0.0343).3FA, MD, λ1, λ2, λ3were significant laterality differences in the putamen (P＜0.05), and all the above diffusion parameters in the left were lower thanthose of in the right. FA, MD, λ1, λ2, λ3were respectively0.1029±0.0186/0.1054±0.0180,7.89±0.37/8.04±0.40,8.71±0.52/8.88±0.56,7.89±0.46/8.05±0.50,7.12±0.44/7.23±0.46in the left and right putamen. FA was significantgender differences in the putamen (P＜0.05), and FA in male was higher thanthat of in female. FA in male and female were0.1073±0.0206/0.0988±0.0154in the left putamen, FA in male and female were0.1090±0.0182/0.1019±0.0172in the right putamen. MD, λ1, λ2, λ3had no gender difference in theputamen. FA, MD, λ1, λ2, λ3were significantly different among age groups inthe putamen (P＜0.05), and all the diffusion parameters were positivelycorrelated with age (P＜0.05).FA, MD, λ1, λ2, λ3had no laterality and gender differences in the globuspallidus (P＞0.05). MD, λ1, λ2, λ3were significantly different among agegroups in the globus pallidus (P＜0.05), and the above diffusion parameterswere positively correlated with age (P＜0.05). FA had no significant linearcorrelation with age in the globus pallidus (P＞0.05).4Phase value was significant laterality difference in the putamen (P＜0.05),and Phase value in the left (-0.1397±0.0550) was lower than that of in theright (-0.1131±0.0522). Phase value had no gender difference in the putamen(P＞0.05). Phase value was significantly different among age groups in theputamen (P＜0.05), and the Phase value was negatively correlated with age (P＜0.05).Phase value was significant laterality difference in the globus pallidal (P＜0.05), and Phase value in the left (-0.1749±0.0341) was lower than that of in the right (-0.1539±0.0313). Phase value had no statistical difference in genderand age groups in the globus pallidal (P＞0.05). Phase value had nosignificant linear correlation with age in the globus pallidus (P＞0.05).5FA, λ1were negatively correlated with Phase value in the left putamen(r=-0.682, P=0.000; r=-0.389, P=0.000). FA, λ1, MD were negativelycorrelated with Phase value in the right putamen (r=-0.676, P=0.000; r=-0.407,P=0.000; r=-0.245, P=0.006). FA, MD, λ1, λ2, λ3had no significant linearcorrelation with Phase value in the globus pallidus.Conclusion:1Phase value can quantitatively estimate the brain iron deposition in vivo.2The differences of FA, MD, λ1, λ2, λ3, Phase value between putamen andglobus pallidus reflect the differences of the microscopic structure and irondeposition.3FA, MD, λ1, λ2, λ3in the right putamen are greater than those of in the left.FA in male are greater than that of in female in the putamen. Diffusionparameters increase with age in the putamen. FA, MD, λ1, λ2, λ3have nodifferences in laterality and gender in the globus pallidus. MD, λ1, λ2, λ3increase with age in the globus pallidus.4Iron concentration in the left putamen and globus pallidus are greater thanthose of in the right. Iron concentration have no differences in gender in theputamen and globus pallidus. Iron concentration increase with age in theputamen, while do not change with age in the globus pallidus.5FA, λ1, MD are positively correlated with iron concentration in the putamen.There are no significant linear correlations between diffusion parameters andiron concentration in the globus pallidus.